Explanation:
What makes
the colours in Jupiter's clouds?
With a mean temperature of
120 degrees Kelvin (-153 degrees Celsius)
and a composition dominated by
hydrogen (about 90%), and helium
(about 10%) with a smattering
of hydrogen compounds like methane and ammonia,
the blue, orange, and brown cloud bands and
the salmon coloured "red" spot are hard to explain.
Trouble is -- at the cool
cloud temperatures
Jupiter's atmospheric constituents should be colourless!
Some suggest that more colourful hydrogen compounds well up from
warmer regions in the atmosphere, tinting the cloud tops.
Alternatively, compounds of trace elements like sulfur may colour the clouds.
Jupiter's
colours do indicate the clouds' altitudes, blue is lowest through
red as highest. The dark coloured
bands are called belts and the light coloured ones zones.
In addition to the
belts and zones,
the Voyager missions revealed
the presence of intricate vortices visible, for example,
in this 1979
image from the Voyager I flyby.
Centuries of visual observations of
Jupiter
have revealed that the colours of its clouds are ever changing.